78, is a chamber opera in one act by Giselher Klebe, to a libretto by his wife Lore Klebe, based on a satire by Mikhail Zoshchenko.

Klebe composed the opera for the 125th anniversary of the opera house of the Staatsoper Hannover in 1977, which was celebrated with three commissions of new works, also Wolfgang Rihm's Faust und Yorick and Karlheinz Stockhausen's Jubiläum for large orchestra.

[1] Klebe's wife, Lore Klebe, wrote the libretto[2] based on the satiric story[1] Ein spaßiges Abenteuer (A funny adventure) by Mikhail Zoshchenko.

[3] The opera was premiered at the opera house in October 1977, staged by Günter Roth [de] and conducted by Hans Herbert Jöris.

Klebe's music has been described as a chamber opera with dramatic drive and economically used sound effects, rhythms and accents.